Biomedical subjects
Publications and source records attributed to H Silva.
During a workshop, hepatologists analyzed and gave recommendations about gallbladder polyps. They arrived to the following agreements: gallbladder polyps of less than 10 mm should be followed with ultrasonography at 3, 6 and 12 months if there is no enlargement. If there is enlargement, a cholecystectomy should be performed. Polyps larger than 10 mm should be subjected to cholecystectomy.
A complementary DNA encoding a salicylic acid (SA)-binding protein has been cloned. Its properties suggest involvement in SA-mediated induction of systemic acquired resistance (SAR) in plants. The sequence of the protein is similar to that of catalases and the protein exhibits catalase activity. Salicylic acid specifically inhibited the catalase activity in vitro and induced an increase in H2O2 concentrations in vivo. H2O2 or compounds, such as SA, that inhibit catalases or enhance the generation of H2O2, induced expression of defense-related genes associated with SAR. Thus, the action of SA in SAR is likely mediated by elevated amounts of H2O2.
After 5 weeks of haloperidol, positive symptoms in drug-naive schizophrenic patients substantially subsided. Negative symptoms, although with a different temporal pattern, decreased after the fifth week of haloperidol treatment; specifically, a decrease was seen in anhedonia and affective flattening, whereas avolition-apathy and attentional impairment presented no changes. Alogia showed a decrease during the third week and a trend to return to placebo scores during weeks 4 and 5. Changes in affective flattening, alogia and attentional impairment correlated with changes in positive symptoms. During placebo, plasma homovanillic acid (HVA) correlated with negative symptoms and with changes presented by negative symptoms between the first and the fifth treatment week. These data show that negative symptoms respond differentially to neuroleptics and suggest that avolition-apathy may represent a different behavioral component of the schizophrenia process.
The presence of hepatitis C virus antibodies was studied in 64 patients with non alcoholic liver disease and found in 11 (17%). The greater frequency of positive antibodies was found among patients with cryptogenetic liver disease, specially those without serum auto-antibodies (32%). The antibody was unusually found (0 to 11%) in non alcoholic liver diseases of other etiologies. It is concluded that hepatitis C virus chronic infections may be the etiology of an important number of non alcoholic chronic liver diseases.
Zipeprol is a non opioid antitussive agent derived from piperazine. In Chile there is an increasing abuse of this drug among youngsters. We report two cases, a 19-years old woman and a 42-years old male, both with personality disorders that used high doses of Zipeprol for hallucinogenic and sedative purposes. The woman had seizures due to the neurotoxic effects of the drug.
The clinical and neuroendocrine evidences that link depression with menopause are reviewed. Climacteric is associated with depressive symptoms, but these do not form a definite depressive entity. Depression would be due to the disregulation of brain noradrenergic and serotoninergic systems. Gonadal steroids modify the neurotransmission of these systems and may influence the mood regulations. Depression appearing in the climacteric period must be treated with antidepressants. The depressive symptoms associated to estrogen deficit may improve with hormonal substitution.
The prevalence and clinical characteristics of depression were studied in 110 randomly chosen patients attending a general medicine outpatient facility. Two psychiatrists evaluated depression according to DSM-III-R criteria and measured the intensity of depression using the Hamilton scale. 25 cases were diagnosed as Mood disorders and 8 as Adaptative disorders. Depression was minor in all cases. Anxiety and somatic complaints were the main symptoms. The influence of the classification system used, demographic and seasonal factors are discussed.
Diagnostic concordance among Rorschach Test, clinical approach and DSM-III-R criteria for BPD is studied in an inpatient sample. A low degree of concordance among the three diagnostic systems was found. Two among 8 DSM-III-R criteria (physically self-damaging acts, and unstable-intense relationships) were the most discriminating symptoms for diagnosing BPD. The importance of considering the diagnostic efficiency of each DSM-III-R criterion is discussed. The most frequent concurrent diagnosis along with BPD were: Affective, and psychotic disorders. Their relationship is analyzed.
Percutaneous sclerotherapy of varicocele was considered in 21 patients with left sided varicocele, 16 of whom had recurrences after left spermatic vein ligation in the past. Percutaneous sclerotherapy was possible in 17 patients (80.9%). There were no serious complications with venography or sclerotherapy, and the recurrence rate was 17.6%. Percutaneous sclerotherapy is therefore a simple, safe and effective treatment of testicular vein insufficiency.
This Latin American study assessed in the general practice setting the efficacy and tolerance of once-daily doxazosin in the treatment of mild or moderate essential hypertension (sitting diastolic blood pressure, 95 to 115 mm Hg). Patients (n = 220) were treated with doxazosin for 12 weeks as monotherapy or in combination with other antihypertensive agents. At the final visit, doxazosin produced a mean change in sitting systolic/diastolic blood pressure of -18.4/-14.4 mm Hg, at a mean daily dose of 4.3 mg. One hundred sixty-three (77.6%) of the 210 evaluable patients were considered a therapeutic success. Lipid analyses identified a statistically significant (p = 0.02) reduction in total serum cholesterol (4.85%) and an overall decrease in triglyceride levels (5.12%). According to the Framingham Heart Study equation, doxazosin produced a highly significant (p less than 0.001) 20% reduction in the calculated probability of developing coronary heart disease in 10 years. Of the 220 patients evaluated, 54 (24.5%) reported side effects that were considered related to treatment. Ten (4.5%) patients reported side effects unrelated to treatment and 37 (16.8%) reported events of unknown relationship. Most side effects were mild or moderate and were tolerated or disappeared with continued treatment. Nine patients (4.1%) were discontinued from therapy and in 13 (5.9%) the dose was reduced. The most prevalent side effects were headache and dizziness. The investigator's overall assessment of antihypertensive efficacy was excellent or good for 176 patients (80.4%); tolerance was considered excellent or good in 193 patients (88.5%).(ABSTRACT TRUNCATED AT 250 WORDS)
A double-blind, parallel, comparative study of the antihypertensive efficacy and safety of once-daily oral doses of amlodipine (5-10 mg/day) vs. twice-daily oral doses of captopril (25-50 mg twice daily) in adult patients with mild or moderate essential hypertension (supine diastolic blood pressure of 95-115 mm Hg) was undertaken in two hospital centers. Interim analysis of data from 40 patients shows that amlodipine and captopril both significantly (p < 0.05) reduced blood pressure compared with baseline. Nineteen of 21 (90.5%) amlodipine-treated patients and 15 of 19 (78.9%) captopril-treated patients had their diastolic blood pressure "normalized" (< 90 mm Hg) with mean final doses of 8.2 and 76.7 mg/day, respectively. At the final visit, there were no statistically significant differences between the two treatment groups in either mean supine or standing blood pressure. Minor nonsignificant changes in standing heart rate were observed in both treatment groups. Seven of the 21 amlodipine-treated patients and 3 of the 19 captopril-treated patients reported adverse experiences. No patients in either treatment group discontinued due to adverse events; one patient in the amlodipine group required a dose reduction. These interim data indicate that the overall efficacy and safety profiles of these two drugs are comparable.
Chemical and morphological changes of incipient to advanced stages of palo podrido, an extensively delignified wood, and other types of white rot decay found in the temperate forests of southern Chile were investigated. Palo podrido is a general term for white rot decay that is either selective or nonselective for the removal of lignin, whereas palo blanco describes the white decayed wood that has advanced stages of delignification. Selective delignification occurs mainly in trunks of Eucryphia cordifolia and Nothofagus dombeyi, which have the lowest lignin content and whose lignins have the largest amount of beta-aryl ether bonds and the highest syringyl/guaiacyl ratio of all the native woods included in this study. A Ganoderma species was the main white rot fungus associated with the decay. The structural changes in lignin during the white rot degradation were examined by thioacidolysis, which revealed that the beta-aryl ether-linked syringyl units were more specifically degraded than the guaiacyl ones, particularly in the case of selective delignification. Ultrastructural studies showed that the delignification process was diffuse throughout the cell wall. Lignin was first removed from the secondary wall nearest the lumen and then throughout the secondary wall toward the middle lamella. The middle lamella and cell corners were the last areas to be degraded. Black manganese deposits were found in some, but not all, selectively delignified samples. In advanced stages of delignification, almost pure cellulose could be found, although with a reduced degree of polymerization. Cellulolytic enzymes appeared to be responsible for depolymerization. A high brightness and an easy refining capacity were found in an unbleached pulp made from selectively delignified N. dombeyi wood. Its low viscosity, however, resulted in poor resistance properties of the pulp. The last stage of degradation (i.e., decomposition of cellulose-rich secondary wall layers) resulted in a gelatinlike substance. Ultrastructural and chemical analyses of this substance showed the matrix to have no microfibrillar structure characteristic of woody cell walls but to still be rich in glucan.
A psychiatric evaluation was performed in 100 patients attending the outpatient clinic of a large general university hospital. Psychiatric diagnosis followed the DSM-III-R criteria. 66 were female and the mean age was 50 years. The clinical diagnosis for the consulting problem related mainly to cardiovascular, metabolic, gastrointestinal and respiratory problems. Some psychiatric disorder was present in 55% of patients, mainly in the area of mood and adaptation problems. A psychiatric diagnosis was made by the general physician in only 14 patients and was labelled as neurosis of anxiety state. Our results show a high prevalence of psychiatric disorders in patients who consult in general clinics. A better psychiatric training of clinicians in charge of primary medical care is needed.
N-methylformamide (NMF) (800-1,000 mg/m2 i.v. day 1) was given to 14 patients with measurable, advanced renal cell carcinoma in this Phase II trial. Treatment was repeated every 28 days. Significant toxicities included drug-induced hepatitis along with moderate nausea and vomiting. No objective responses were seen although several patients had stable disease with treatment for prolonged periods. NMF is not an active agent in renal cell cancer when administered by this schedule.
Patients with recurrent and metastatic squamous cell carcinoma of the head and neck (SCCHN) were stratified by performance status, extent of disease, and prior radiotherapy and subsequently randomized to receive carboplatin (CBDCA; Bristol-Myers, Wallingford, CT) administered intravenously (IV) monthly, initially at doses of 400 mg/m2 in combination with methotrexate (MTX) given IV weekly at doses of 40 mg/m2 or MTX alone at the same dose/schedule. Significant dose-limiting myelosuppression required CBDCA dose reductions to 300 mg/m2 and, subsequently, 200 mg/m2. Nonhematological toxicities were not significant. Our study objective was to determine whether CBDCA plus MTX produce a substantial improvement in response rate over single-agent MTX. A response rate of 50% (complete [CR] plus partial response [PR]) for CBDCA plus MTX compared with 25% for MTX was specified as the difference to be detected. We employed a two-stage study design for randomized trials that allowed for early termination of studies involving relatively ineffective treatment regimens. With this design, the study could be closed after the first stage (20 patients entered onto each treatment arm) if the number of responders to CBDCA plus MTX were not superior to MTX. Five of 20 patients responded to treatment in each arm, and we were able to conclude that the addition of CBDCA to MTX is unlikely to result in a twofold increase in response rate compared with MTX alone in this group of patients. This two-stage design represents a simple and efficient method of testing the relative efficacy of new combinations containing at least one active agent against a suitable control arm in this disease. It addresses scientific and ethical issues of continuing testing with relatively ineffective treatments, and at the same time provides a reliable method for identifying very active regimens likely to represent significant therapeutic advances.
The antihypertensive efficacy and safety of doxazosin, a selective alpha 1-inhibitor, were assessed in 33 severely hypertensive patients. The study involved three phases: a 1-day baseline period, a 32-day period in which patients received doxazosin, 1 to 16 mg, once daily, and a 4-week maintenance period. All patients were considered therapy successes (sitting diastolic blood pressure either less than or equal to 90 mm Hg or greater than or equal to 10 mm Hg reduction) at a mean daily dose of 8.1 mg. Twenty-seven patients (82%) achieved good blood pressure control (sitting diastolic blood pressure less than or equal to 90 mm Hg) at a mean dose of 6.7 mg once daily. By the final treatment visit, mean systolic/diastolic blood pressures in the sitting and supine positions were significantly reduced by 40/29 and 37/28 mm Hg from a mean baseline of 180/121 and 181/121 mm Hg to final visit values of 140/91 and 144/92 mm Hg, respectively (p less than 0.05). Eleven patients experienced one or more side effects that were mild or moderate and disappeared or were tolerated with continued therapy. During the study no abnormal laboratory test findings were identified by the investigators. The investigators' global assessment of the efficacy and toleration of once-daily doxazosin therapy was excellent or good for 31 (94%) patients and fair for the remaining two patients.
Explore the source record for details and available documents.
A patient with a renal transplant who was receiving immunosuppressive therapy developed the adult respiratory distress syndrome (ARDS). Numerous filariform larvae of Strongyloides stercoralis were seen in the bronchial lavage. The patient died despite intensive treatment, and the postmortem examination revealed abundant larvae of the parasite in the lungs. There were no other factors that could explain the ARDS.